fix: 修复迁移后的基础UI显示问题

app/lib/src/ui/game_canvas.dart

@@ -1,25 +1,45 @@
-// 游戏画布：把 World 在 800×608 虚拟分辨率下的渲染做信箱（letterbox）缩放。
+// 游戏画布：把 World 的虚拟视口渲染铺满整个屏幕（全屏、无信箱黑边）。
+// 虚拟视口保证 800×608 始终完整可见（不裁游戏内容），另一维随屏幕比例
+// 自动加宽：例如 2340×1080 的横屏手机 → 视口约 1318×608（横向看得更多），
+// 与 PC 游戏支持任意宽高比的做法一致。
 import 'dart:ui' show Canvas, Rect, Paint, Color;
-import 'dart:math' show min;
 import 'package:flutter/widgets.dart';
 import 'package:flutter/foundation.dart' show debugPrint;
 import 'package:iwbtc/src/core/app_error.dart' show AppError;
 import 'package:iwbtc/src/game/world.dart' show World, W, H;
 
-/// 计算 800×608 虚拟画面在给定屏幕尺寸下的信箱矩形（居中、等比缩放）。
-///
-/// 画布和虚拟手柄都用它：横屏手机宽高比远大于画面比例，两侧会出现黑边，
-/// 手柄按钮必须锚定在**画面区域**内，否则会漂到黑边上（手指按到的位置和
-/// 屏幕上看到的游戏内容对不上）。尺寸非法（尚未布局完成）时返回 Rect.zero。
-Rect letterboxRect(Size size) {
-  if (!size.width.isFinite || !size.height.isFinite) return Rect.zero;
-  if (size.width <= 0 || size.height <= 0) return Rect.zero;
-  final s = min(size.width / W, size.height / H);
-  if (!s.isFinite || s <= 0) return Rect.zero;
-  final double w = W * s;
-  final double h = H * s;
-  return Rect.fromLTWH(
-      (size.width - w) / 2, (size.height - h) / 2, w, h);
+/// 屏幕对应的虚拟视口：缩放系数 + 视口尺寸（虚拟像素）。
+class StageMetrics {
+  final double scale;
+  final double vw;
+  final double vh;
+  const StageMetrics(this.scale, this.vw, this.vh);
+
+  bool get isValid =>
+      scale > 0 &&
+      scale.isFinite &&
+      vw.isFinite &&
+      vh.isFinite &&
+      vw >= W - 0.5 &&
+      vh >= H - 0.5;
+}
+
+/// 计算铺满全屏的虚拟视口（无黑边），且保证 800×608 完整可见：
+/// - 屏幕比游戏「更宽」（横屏手机几乎总是如此）→ 高度定标 608，
+///   视口横向加宽到 vw = 屏宽 / scale，游戏内容横向看得更多；
+/// - 屏幕比游戏「更窄」→ 宽度定标 800，视口纵向加高到 vh = 屏高 / scale。
+/// 摄像机随后按视口尺寸取景（Camera 自带对关卡边界的钳制）。
+StageMetrics stageMetrics(Size size) {
+  if (!size.width.isFinite || !size.height.isFinite) {
+    return const StageMetrics(0, 0, 0);
+  }
+  if (size.width <= 0 || size.height <= 0) return const StageMetrics(0, 0, 0);
+  if (size.width / size.height >= W / H) {
+    final s = size.height / H;
+    return StageMetrics(s, size.width / s, H);
+  }
+  final s = size.width / W;
+  return StageMetrics(s, W, size.height / s);
 }
 
 class GameCanvas extends StatelessWidget {
@@ -32,9 +52,7 @@ class GameCanvas extends StatelessWidget {
     // 用 SizedBox.expand 明确占满父级，避免 CustomPaint 使用 Size.infinite
     // 时在部分平台上拿到零尺寸/无穷尺寸，算出 scale = 0 而整屏消失（表现为黑屏）。
     return SizedBox.expand(
-      child: CustomPaint(
-        painter: _GamePainter(world, repaint),
-      ),
+      child: CustomPaint(painter: _GamePainter(world, repaint)),
     );
   }
 }
@@ -48,21 +66,21 @@ class _GamePainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-    // 信箱外框（黑色）
-    canvas.drawRect(
-        Rect.fromLTWH(0, 0, size.width, size.height),
-        Paint()..color = const Color(0xff000000));
+    // 首帧可能尚未完成布局，尺寸为 0 时不要绘制内容（stageMetrics 无效）。
+    final m = stageMetrics(size);
+    if (!m.isValid) return;
 
-    // 首帧可能尚未完成布局，尺寸为 0 时不要绘制内容（letterboxRect 返回 zero）。
-    final rect = letterboxRect(size);
-    if (rect.isEmpty) return;
+    // 同步虚拟视口（只改纯数值字段，不触发任何通知 —— paint 阶段禁止 notifier）。
+    world.setViewport(m.vw, m.vh);
 
     canvas.save();
-    canvas.translate(rect.left, rect.top);
-    canvas.scale(rect.width / W, rect.width / W);
-    canvas.clipRect(Rect.fromLTWH(0, 0, W, H));
+    canvas.scale(m.scale);
+    canvas.clipRect(Rect.fromLTWH(0, 0, m.vw, m.vh));
+    // 兜底底色：即使 world.render 抛异常也不会露出透明/白屏。
     canvas.drawRect(
-        Rect.fromLTWH(0, 0, W, H), Paint()..color = const Color(0xff0a0a14));
+      Rect.fromLTWH(0, 0, m.vw, m.vh),
+      Paint()..color = const Color(0xff0a0a14),
+    );
     // 渲染异常原本会被静默吞掉，画面变成纯黑。
     // 偶发的一帧异常不该让整局报废 —— 只记录日志；但若连续多帧都失败
     // （比如某张地图/某种渲染路径真有问题），才升级成占屏错误以便真机诊断。
@@ -84,9 +102,10 @@ class _GamePainter extends CustomPainter {
     if (!_loggedFirstPaint) {
       _loggedFirstPaint = true;
       debugPrint(
-          '[boot] canvas rendered: screen=${size.width}x${size.height} '
-          'stage=${rect.width}x${rect.height} at (${rect.left},${rect.top}) '
-          'state=${world.state}');
+        '[boot] canvas rendered: screen=${size.width}x${size.height} '
+        'viewport=${m.vw.toStringAsFixed(0)}x${m.vh.toStringAsFixed(0)} '
+        'state=${world.state}',
+      );
     }
   }
 

app/lib/src/ui/touch_controls.dart

@@ -2,20 +2,19 @@
 import 'dart:async';
 import 'package:flutter/widgets.dart';
 import 'package:iwbtc/src/core/input.dart' show Input;
-import 'package:iwbtc/src/ui/touch_layout.dart'
-    show BUTTONS, metaSettings;
+import 'package:iwbtc/src/ui/touch_layout.dart' show BUTTONS, metaSettings;
 import 'package:iwbtc/src/game/world.dart' show World, W;
-import 'package:iwbtc/src/ui/game_canvas.dart' show letterboxRect;
 
 class TouchControls extends StatelessWidget {
   final World world;
   final ValueNotifier<bool> visible;
   final ValueNotifier<bool> hasGun;
-  const TouchControls(
-      {super.key,
-      required this.world,
-      required this.visible,
-      required this.hasGun});
+  const TouchControls({
+    super.key,
+    required this.world,
+    required this.visible,
+    required this.hasGun,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -24,11 +23,10 @@ class TouchControls extends StatelessWidget {
       valueListenable: visible,
       builder: (_, bool v, __) {
         if (!v) return const SizedBox();
-        // 按钮锚定在「信箱缩放后的画面矩形」内，而不是整块屏幕：
-        // 横屏时两侧是黑边，若按全屏百分比定位，左/右/跳跃键会飘到黑边上。
+        // 画面已铺满全屏（无信箱黑边），按钮直接按整屏百分比定位。
         return LayoutBuilder(
           builder: (_, BoxConstraints cons) {
-            final area = letterboxRect(Size(cons.maxWidth, cons.maxHeight));
+            final area = Rect.fromLTWH(0, 0, cons.maxWidth, cons.maxHeight);
             return Stack(
               children: <Widget>[
                 for (final b in BUTTONS)
@@ -68,17 +66,18 @@ class _TouchButton extends StatefulWidget {
   /// 空 Rect 表示尚未完成布局，此时不渲染。
   final Rect area;
 
-  const _TouchButton(
-      {required this.world,
-      required this.keyName,
-      required this.label,
-      this.label2,
-      required this.shape,
-      required this.cx,
-      required this.cy,
-      required this.size,
-      required this.hasGun,
-      required this.area});
+  const _TouchButton({
+    required this.world,
+    required this.keyName,
+    required this.label,
+    this.label2,
+    required this.shape,
+    required this.cx,
+    required this.cy,
+    required this.size,
+    required this.hasGun,
+    required this.area,
+  });
 
   @override
   State<_TouchButton> createState() => _TouchButtonState();
@@ -114,8 +113,14 @@ class _TouchButtonState extends State<_TouchButton> {
   }
 
   void _release() {
-    if (!_pressed) return;
-    _pressed = false;
+    // 注意：即便 _pressed 因事件丢失而处于异常状态，也要强制复位虚拟键，
+    // 否则 touch['jump'] 会卡在 true（漏接松手事件时极易发生），
+    // 之后每次按下都因 setTouch 的「值未变则直接 return」短路而触发不了
+    // 新的边沿 —— 表现就是「跳跃键经常失灵、时好时坏」。
+    if (_pressed) {
+      _pressed = false;
+      setState(() {});
+    }
     _shootTimer?.cancel();
     _shootTimer = null;
     final a = widget.keyName;
@@ -124,7 +129,6 @@ class _TouchButtonState extends State<_TouchButton> {
     } else {
       Input.setTouch(a, false);
     }
-    setState(() {});
   }
 
   @override
@@ -143,10 +147,15 @@ class _TouchButtonState extends State<_TouchButton> {
       top: top,
       width: sz,
       height: sz,
-      child: Listener(
-        onPointerDown: (_) => _press(),
-        onPointerUp: (_) => _release(),
-        onPointerCancel: (_) => _release(),
+      // 用 GestureDetector（Pan 识别器会「认领」指针）替代 Listener：
+      // Listener 不捕获指针，手指在按钮上滑动后于按钮外松手时，松手事件
+      // 落到别的控件上 → 本按钮的虚拟键永久卡在按下态。Pan 会持续把
+      // 抬起/取消事件回传给本按钮，松手必定复位。
+      child: GestureDetector(
+        behavior: HitTestBehavior.opaque,
+        onPanDown: (_) => _press(),
+        onPanEnd: (_) => _release(),
+        onPanCancel: () => _release(),
         child: ValueListenableBuilder<bool>(
           valueListenable: widget.hasGun,
           builder: (_, __, ___) {
@@ -160,23 +169,28 @@ class _TouchButtonState extends State<_TouchButton> {
                       : const Color(0x444a5a7a),
                   shape: isJump ? BoxShape.circle : BoxShape.rectangle,
                   borderRadius: isJump ? null : BorderRadius.circular(sz * 0.3),
-                  border: Border.all(
-                      color: const Color(0xff7ae0ff), width: 2),
+                  border: Border.all(color: const Color(0xff7ae0ff), width: 2),
                 ),
                 child: Center(
                   child: Column(
                     mainAxisSize: MainAxisSize.min,
                     children: <Widget>[
-                      Text(widget.label,
-                          style: TextStyle(
-                              color: const Color(0xffffffff),
-                              fontSize: sz * 0.32,
-                              fontWeight: FontWeight.bold)),
+                      Text(
+                        widget.label,
+                        style: TextStyle(
+                          color: const Color(0xffffffff),
+                          fontSize: sz * 0.32,
+                          fontWeight: FontWeight.bold,
+                        ),
+                      ),
                       if (widget.label2 != null)
-                        Text(widget.label2!,
-                            style: TextStyle(
-                                color: const Color(0xffcfe8ff),
-                                fontSize: sz * 0.16)),
+                        Text(
+                          widget.label2!,
+                          style: TextStyle(
+                            color: const Color(0xffcfe8ff),
+                            fontSize: sz * 0.16,
+                          ),
+                        ),
                     ],
                   ),
                 ),

app/lib/src/ui/touch_editor.dart

@@ -0,0 +1,299 @@
+// 触屏手柄布局编辑器：独立全屏页，从「设置 → 自定义按键」进入。
+// 背景保持透明，透出下面的实时游戏画布（标题星空 + 刺地带动画），
+// 编辑体验与正常玩游戏时完全一致（同样的全屏沉浸、同样的按钮渲染）。
+//
+// 布局即改即存（每次拖动/缩放都写回存档），返回时无需再点「确定」。
+// 位置/大小与真实手柄同一套换算（cx/cy 百分比 + size×k），所见即所得。
+import 'package:flutter/material.dart';
+import 'package:iwbtc/src/core/save.dart' show Save;
+import 'package:iwbtc/src/game/world.dart' show W;
+import 'package:iwbtc/src/ui/touch_layout.dart'
+    show BUTTONS, TouchBtn, metaSettings;
+
+/// 读取某按键当前布局（cx/cy/size）。
+Map<String, double> touchLayoutOf(String key) {
+  final t = metaSettings()['touch'] as Map;
+  final m = (t[key] as Map?) ?? const <String, dynamic>{};
+  return <String, double>{
+    'cx': double.tryParse(m['cx'].toString()) ?? 50,
+    'cy': double.tryParse(m['cy'].toString()) ?? 50,
+    'size': double.tryParse(m['size'].toString()) ?? 60,
+  };
+}
+
+void writeTouchLayout(String key, Map<String, double> p) {
+  (metaSettings()['touch'] as Map)[key] = <String, dynamic>{
+    'cx': p['cx'],
+    'cy': p['cy'],
+    'size': p['size'],
+  };
+  // 即改即存：布局写回存档，返回/切后台都不会丢。
+  Save.flush();
+}
+
+class TouchLayoutEditor extends StatefulWidget {
+  final VoidCallback onDone; // 仅负责返回设置页（布局已即改即存）
+  const TouchLayoutEditor({super.key, required this.onDone});
+  @override
+  State<TouchLayoutEditor> createState() => _TouchLayoutEditorState();
+}
+
+class _TouchLayoutEditorState extends State<TouchLayoutEditor> {
+  @override
+  Widget build(BuildContext context) {
+    // 背景保持透明：透出下面的实时游戏画布（标题星空+刺地），
+    // 编辑体验与正常游戏完全一致（全屏沉浸）。
+    return Stack(
+      children: <Widget>[
+        // 按钮编辑层（铺满全屏，与真实手柄同一坐标系）
+        Positioned.fill(
+          child: LayoutBuilder(
+            builder: (BuildContext _, BoxConstraints cons) {
+              final double w = cons.maxWidth;
+              final double h = cons.maxHeight;
+              // 与 _TouchButton 完全一致的缩放系数，保证编辑所见 = 游戏所得
+              final double k = (w / W).clamp(0.6, 2.6);
+              return Stack(
+                children: <Widget>[
+                  for (final b in BUTTONS) ...<Widget>[
+                    _EditBtn(
+                      b: b,
+                      k: k,
+                      screenW: w,
+                      screenH: h,
+                      onChanged: () => setState(() {}),
+                    ),
+                    _ResizeHandle(
+                      b: b,
+                      k: k,
+                      screenW: w,
+                      screenH: h,
+                      onChanged: () => setState(() {}),
+                    ),
+                  ],
+                ],
+              );
+            },
+          ),
+        ),
+        // 顶部操作行：恢复默认 / 返回
+        Positioned(
+          top: 10,
+          right: 12,
+          child: Row(
+            children: <Widget>[
+              ElevatedButton(
+                onPressed: () {
+                  final t = metaSettings()['touch'] as Map;
+                  t.clear();
+                  for (final b in BUTTONS) {
+                    t[b.key] = <String, dynamic>{
+                      'cx': b.cx,
+                      'cy': b.cy,
+                      'size': b.size,
+                    };
+                  }
+                  Save.flush();
+                  setState(() {});
+                },
+                style: ElevatedButton.styleFrom(
+                  backgroundColor: const Color(0x991a1a26),
+                  foregroundColor: const Color(0xffffffff),
+                  padding: const EdgeInsets.symmetric(
+                    horizontal: 12,
+                    vertical: 6,
+                  ),
+                  minimumSize: Size.zero,
+                  tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+                  visualDensity: VisualDensity.compact,
+                ),
+                child: const Text('恢复默认', style: TextStyle(fontSize: 13)),
+              ),
+              const SizedBox(width: 8),
+              ElevatedButton(
+                onPressed: widget.onDone,
+                style: ElevatedButton.styleFrom(
+                  backgroundColor: const Color(0x995a3a7a),
+                  foregroundColor: const Color(0xffffffff),
+                  padding: const EdgeInsets.symmetric(
+                    horizontal: 14,
+                    vertical: 6,
+                  ),
+                  minimumSize: Size.zero,
+                  tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+                  visualDensity: VisualDensity.compact,
+                ),
+                child: const Text('返回', style: TextStyle(fontSize: 13)),
+              ),
+            ],
+          ),
+        ),
+        // 底部提示
+        const Positioned(
+          left: 0,
+          right: 0,
+          bottom: 8,
+          child: Center(
+            child: Text(
+              '点选按钮后可拖动位置 · 拖右下角黄点调整大小（改动即时保存）',
+              style: TextStyle(color: Color(0x88ffffff), fontSize: 12),
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _EditBtn extends StatefulWidget {
+  final TouchBtn b;
+  final double k; // 真实手柄同款缩放系数
+  final double screenW;
+  final double screenH;
+  final VoidCallback onChanged;
+  const _EditBtn({
+    required this.b,
+    required this.k,
+    required this.screenW,
+    required this.screenH,
+    required this.onChanged,
+  });
+  @override
+  State<_EditBtn> createState() => _EditBtnState();
+}
+
+class _EditBtnState extends State<_EditBtn> {
+  bool _selected = false;
+
+  @override
+  Widget build(BuildContext context) {
+    final p = touchLayoutOf(widget.b.key);
+    final double sz = p['size']! * widget.k;
+    final double left = p['cx']! / 100 * widget.screenW - sz / 2;
+    final double top = p['cy']! / 100 * widget.screenH - sz / 2;
+    final isJump = widget.b.shape == 'jump';
+    return Positioned(
+      left: left,
+      top: top,
+      width: sz,
+      height: sz,
+      child: GestureDetector(
+        behavior: HitTestBehavior.opaque,
+        onTap: () => setState(() => _selected = !_selected),
+        onPanStart: (_) => setState(() => _selected = true),
+        onPanUpdate: (d) {
+          final np = touchLayoutOf(widget.b.key);
+          np['cx'] = (np['cx']! + d.delta.dx / widget.screenW * 100).clamp(
+            3.0,
+            97.0,
+          );
+          np['cy'] = (np['cy']! + d.delta.dy / widget.screenH * 100).clamp(
+            4.0,
+            96.0,
+          );
+          writeTouchLayout(widget.b.key, np);
+          widget.onChanged();
+        },
+        child: Container(
+          decoration: BoxDecoration(
+            color: _selected
+                ? const Color(0x88ffffff)
+                : const Color(0x444a5a7a),
+            shape: isJump ? BoxShape.circle : BoxShape.rectangle,
+            borderRadius: isJump ? null : BorderRadius.circular(sz * 0.3),
+            border: Border.all(
+              color: _selected
+                  ? const Color(0xffffd23a)
+                  : const Color(0xff7ae0ff),
+              width: 2,
+            ),
+          ),
+          child: Center(
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: <Widget>[
+                Text(
+                  widget.b.label,
+                  style: TextStyle(
+                    color: const Color(0xffffffff),
+                    fontSize: sz * 0.3,
+                    fontWeight: FontWeight.bold,
+                  ),
+                ),
+                if (widget.b.label2 != null)
+                  Text(
+                    widget.b.label2!,
+                    style: TextStyle(
+                      color: const Color(0xffcfe8ff),
+                      fontSize: sz * 0.15,
+                    ),
+                  ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+/// 缩放手柄：选中按钮后显示在其右下角的小黄点，拖动改变按钮大小。
+/// 单独一层 Positioned（在按钮之后 = 绘制在上层），不吃按钮本体的手势。
+class _ResizeHandle extends StatefulWidget {
+  final TouchBtn b;
+  final double k;
+  final double screenW;
+  final double screenH;
+  final VoidCallback onChanged;
+  const _ResizeHandle({
+    required this.b,
+    required this.k,
+    required this.screenW,
+    required this.screenH,
+    required this.onChanged,
+  });
+  @override
+  State<_ResizeHandle> createState() => _ResizeHandleState();
+}
+
+class _ResizeHandleState extends State<_ResizeHandle> {
+  bool _active = false;
+
+  @override
+  Widget build(BuildContext context) {
+    final p = touchLayoutOf(widget.b.key);
+    final double sz = p['size']! * widget.k;
+    final double left = p['cx']! / 100 * widget.screenW + sz / 2 - 14;
+    final double top = p['cy']! / 100 * widget.screenH + sz / 2 - 14;
+    return Positioned(
+      left: left,
+      top: top,
+      width: 26,
+      height: 26,
+      child: GestureDetector(
+        behavior: HitTestBehavior.opaque,
+        onPanStart: (_) => setState(() => _active = true),
+        onPanEnd: (_) => setState(() => _active = false),
+        onPanCancel: () => setState(() => _active = false),
+        onPanUpdate: (d) {
+          final np = touchLayoutOf(widget.b.key);
+          // 向右/向下拖 = 变大，换算回虚拟 size 单位
+          final double dSize = (d.delta.dx + d.delta.dy) / widget.k;
+          np['size'] = (np['size']! + dSize).clamp(30.0, 180.0);
+          writeTouchLayout(widget.b.key, np);
+          widget.onChanged();
+        },
+        child: Container(
+          decoration: BoxDecoration(
+            color: _active ? const Color(0xffffd23a) : const Color(0xccffd23a),
+            shape: BoxShape.circle,
+            border: Border.all(color: const Color(0xff2a2a3a), width: 1.5),
+          ),
+          child: const Center(
+            child: Icon(Icons.open_in_full, size: 14, color: Colors.black87),
+          ),
+        ),
+      ),
+    );
+  }
+}

app/lib/src/ui/touch_layout.dart

@@ -10,18 +10,29 @@ class TouchBtn {
   final double cx;
   final double cy;
   final double size;
-  const TouchBtn(this.key, this.label, this.shape, this.cx, this.cy, this.size,
-      [this.label2]);
+  const TouchBtn(
+    this.key,
+    this.label,
+    this.shape,
+    this.cx,
+    this.cy,
+    this.size, [
+    this.label2,
+  ]);
 }
 
+// 默认布局仿照主流 IWBT 手游截图：左下 ◀▶ 并排、右侧大「跳」、
+// 左下角🔫射击 / 右下角▼下蹲、右中上 ↺ 自杀、右上角 ❚❚ 暂停。
 const List<TouchBtn> BUTTONS = <TouchBtn>[
-  TouchBtn('left', '◀', 'round', 12, 80, 62),
-  TouchBtn('right', '▶', 'round', 24, 80, 62),
-  TouchBtn('jump', '跳', 'jump', 88, 84, 94),
-  TouchBtn('shoot', '🔫', 'item', 79, 72, 54, '射击'),
-  TouchBtn('down', '▼', 'item', 90, 72, 54, '下蹲'),
-  TouchBtn('pause', '❚❚', 'sm', 81, 58, 42),
-  TouchBtn('suicide', '↺', 'sm', 90, 58, 42),
+  TouchBtn('left', '◀', 'round', 12.5, 81, 62),
+  TouchBtn('right', '▶', 'round', 22, 81, 62),
+  TouchBtn('shoot', '🔫', 'item', 78.5, 90, 56, '射击'),
+  TouchBtn('down', '▼', 'item', 94.5, 89, 56, '下蹲'),
+  TouchBtn('pause', '❚❚', 'sm', 96.5, 8, 40),
+  TouchBtn('suicide', '↺', 'sm', 91, 56, 52),
+  // 跳跃键放最后（绘制在最上层）：即便与其它键像素重叠，重叠区也优先归跳跃键，
+  // 避免按下跳跃时落到射击/下蹲键上导致「跳跃键失灵」。
+  TouchBtn('jump', '跳', 'jump', 85, 73, 78),
 ];
 
 const List<List<String>> KEY_ACTIONS = <List<String>>[
@@ -38,32 +49,28 @@ const List<List<String>> KEY_ACTIONS = <List<String>>[
 Map<String, dynamic> defaultTouch() {
   final m = <String, dynamic>{};
   for (final b in BUTTONS) {
-    m[b.key] = <String, dynamic>{
-      'cx': b.cx,
-      'cy': b.cy,
-      'size': b.size,
-    };
+    m[b.key] = <String, dynamic>{'cx': b.cx, 'cy': b.cy, 'size': b.size};
   }
   return m;
 }
 
 Map<String, dynamic> defaultSettings() => <String, dynamic>{
-      'username': '',
-      'touch': defaultTouch(),
-      'keys': defaultBindings(),
-    };
+  'username': '',
+  'touch': defaultTouch(),
+  'keys': defaultBindings(),
+};
 
 Map<String, List<String>> defaultBindings() => <String, List<String>>{
-      'left': <String>['ArrowLeft', 'KeyA'],
-      'right': <String>['ArrowRight', 'KeyD'],
-      'up': <String>['ArrowUp', 'KeyW'],
-      'down': <String>['ArrowDown', 'KeyS'],
-      'jump': <String>['ShiftLeft', 'ShiftRight', 'Space', 'KeyZ', 'KeyN'],
-      'shoot': <String>['KeyX', 'KeyJ', 'KeyC', 'KeyM'],
-      'suicide': <String>['KeyR'],
-      'restart': <String>['Backspace'],
-      'pause': <String>['Escape', 'KeyP'],
-    };
+  'left': <String>['ArrowLeft', 'KeyA'],
+  'right': <String>['ArrowRight', 'KeyD'],
+  'up': <String>['ArrowUp', 'KeyW'],
+  'down': <String>['ArrowDown', 'KeyS'],
+  'jump': <String>['ShiftLeft', 'ShiftRight', 'Space', 'KeyZ', 'KeyN'],
+  'shoot': <String>['KeyX', 'KeyJ', 'KeyC', 'KeyM'],
+  'suicide': <String>['KeyR'],
+  'restart': <String>['Backspace'],
+  'pause': <String>['Escape', 'KeyP'],
+};
 
 /// 读取/补全存档里的设置对象（保证 touch / keys 字段齐全）。
 Map<String, dynamic> metaSettings() {